This invention relates to improved natural and synthetic rubber compositions, and to methods for preparing the same.
It is known in the art to employ mineral oil as a plasticizer or extender for rubbery materials including both natural rubber and synthetic rubber such as butadiene polymers and interpolymers, etc., and such oils generally impart highly satisfactory properties to the rubbery material in question. However, rubbery materials plasticized with mineral oil plasticizers of the prior art exhibit a disadvantageous tendency to stain materials adjacent to the rubbery material. Furthermore, in the case of light-colored rubber products, e.g., white sidewall tires for automobiles, footwear, etc. rubbery materials plasticized with prior art mineral oil plasticizers show a disadvantageously poor color stability, particularly upon aging in bright sunlight.